The Microscopy and Molecular Cytochemistry Core (Core C) will provide instrumentation, expertise and service as related to microscopy, cytochemistry, immunocytochemistry, cytopathology, histochemistry and photography as needed by each of the four project components. This core will provide the following specific functions; (1) instrumentation and technical expertise on conventional bright field and epifluorescence microscopy, Laser Scanning Confocal Microscopy and image analysis, (2) hist and cytochemistry, immunocytochemistry, paraffin and frozen sections, special staining procedures, and in situ hybridization, (3) electron microscopy and, (4) photography including black and white or color prints, development of 35 mm film, darkroom procedures and photographic copying and macro-photography of dyeinjected mammary glands and whole animals. The core leader and personnel will be available to provide assistance and advice on experimental designs as related to any technique or procedure in microscopy and cytochemistry.